Constant-current regulator.



n. A. A. TIRRILL. CONSTANT CURRENT REGULATOR. APILIOATION FILED DEOVM,1907.

1,098,649, Patented June 2, 1914.

:Illljlflllllflll IIIIITIIIIIIMIIL Z n Inventor; Zllen -JI Tirrill, w.@Mw-1M;-

UNITED s TArEs 'Pa'rENr OFFICE.

ALLEN A. TUIEEILL, or soHENEoTADY, NEW YORK, 'AssIGnoR .TCGENEEALELECTRIC COMPANY, -A CoEPo-EATICN oF NEW YORK.

`Bc it. Vknown that=-I, ALLEN iLTmRILL, a citizen of the: United States,residing at Schenectady, coun-ty of Schenectady, State of New York,have' invented cert-ain new and useful linl'n'ovements inConstant-Current Regulators, of which the following is a specification.

My invention rel ates to` regulators :for systenis oi electricdistribution comprising dyn'aino electric machines, such boosters, inwhich the voltage delivered by the machine is automati'ally varied inresponse to conditionsl on the system, and more particularly toregulatorsl for systems in which a storage battery is used-to equalizethe load on the generator sul'iplyin; the system, and the charging anddischarging of the battery isv regulated by a booster connected inseries with'it.

Boosters or similar machines have been regulated by varvin f both thedirection and amount ot' current owing through the ield coil oi' themachine by means of two rheo- 'stats, one controlling the flow ofcurrent through `the coil in one direction, and they other controllingthe flow of current in the opposite direction. i`his arrangement iscostly and ineicieiit. since cach rheostat must be large enough to`control the maximum amount ot current through the coil, the regulationis sluggish and the current continually varies. since the rheostatcannot compensate quickly-and accurately for slight changes in current.l

`lhe obiect ot' my invention is to provide a simple and -eicientregulator, which controis both thedireotion and amount of magnctoniotiveforce dvelopedin the field of the booster or similar machine, whichaccurately and ,instantaneously varies the voltage of the machine byvarying the length of Atime during which the Held winding is-'energized,which avoids the necessity of con stantly` siiiiing a heavy rheostatarm, which when used with a booster in series wlth a storage batterywill automatically throw the Specification of'Letters Patent.'

' CONSTANT-CURRENT REGULATOR.

or similar machine is provided with means Patented J ulieZ, 1914.Appiication inea December 14, 1907. serial No. 406,429.

for producing a magnetomotive force in either direction -in the field,and both the direction and dura-tion of the' magnetomotive force areunder constant control of an automatic device instantly responsive tochanges in load or other conditions on the circuit.

Inthe. preferred arrangement, a single field lcoil is arranged so thatcurrent may be sent through the coil in either direction. The durationof the linx set up in the field of the machine by the current in thefield coil isvaried by interrupting the flow of current,

preferably by an automatic device responsive to load ontlie'machine,-.Wliich opens and closes either the circuit of the field`coil or preferably a shunt circuit 4around a resist' ance 1n series withthe field coil.

The. automatic device is preferably what i is known in the art as aTirrill regulator' and closes the circuit for energizing the field coilseveral hundred times per minute, automatically changing the length ofthe periods 'ot' time `during which the circuit is closed and alsochanging the intervals between those periods so that conditionsiion .thecireuit'may be varied from' one extreme where the circuit is closed forcomparatively long periods of time and opened only for an instantbetween periods, whereby nearly the same current flows -as though thecircuit were continuously closed, to the other exi treme where theVcircuit is closed only for 4an instant and. the intervals between V theperiods of closed circuit are so long that very little current flows.Thefrate at which the circuit is opened and closed may also be 'variedso that a very complete and accurate control of` thc circuit is secured.The 'device lnot only controls the amount of excitation .of the ieldcoil but also controls the direction of current through the. field sothat' the voltage of the booster is varied, both in direction and amountto control both the' chargingand discharging of the battery.

If the booster or similar dynamo electric machine is large, an excitermay be directly connected tothe single field coil ofthe ma.-

chine, and the exciter provided with a 4single field coil with twosupply circuits for causing a current to iow in .either direction, thekduration. of current in either direction being' controlled by anautomatic device responsive both to load on the circuit supplied" bythe..

ilA

machine and also tri-voltage on the exciter circuit, and arranged toopen and close 1ntermittently either supply circuit for the field coilof' the exciter.

In the,k accompanying drawing, which shows one embodiment o f myinvention, the figure shows a regulator applied to a booster in serieswith a storage battery, the field of the booster being. energized bymeans of an exciter.

In the arrangement shown, a generatorI 1 supplies current to/a'consumption circuit having leads 2 andl 3, and the load on thegenerator is equalized by means oit' a storage battery 4 connectedacross the consumption circuit in parallel with the generator 1. Inorder to control the'outpu't ot the storage battery and insure that itshall always take its share of. the load and also to charge itwithoutraising the voltage of the entire system, Va booster 5,;connected inseries with the battery, is proyided with regulating means for causing`the booster to generate a voltage, which willy either assist lor opposethe discharge of the battery. As here shown 4the booster 5 is provided,with a field coil Gb directly connected in circuit with the armature 6ILof an exciter having a single field coil (i. rl`hrough this single fieldcoil G cur rent may flow in eitherdirection from either of two supplycircuits. @ne end of the field coil G is connected through a lead -tothe middle of the battery et. while the other end of the coil isconnected to both ends ot the battery, so that current liows in onedirection fromone end of the battery to the middle through one supplycircuit comprising a lead 8 from one end of the battery, adjust-.- ableresistance 9, a lead 10, field coil G andy lead 7 to the middle of thebattery, and in the other direction from the middle of the.

battery to the other end through a second circuit comprising the leadi", field coil G, leads 10 and 1l, adjustable resistance 9 and a leadS"L to the other end of the battery.

In order to control the duration and direcin the field of the exciterand hence in the .field of the booster, vthe flow ot current through thefield coil (3 from either supply circuit is intermittentlyv interruptedin any suitable Way, preferably by intermittentlyv cutting resistance 9or 9 out of circuit as the case may be with the field coil bymeans ofshunt circuits, one comprising leads 12 and 13 connected to oppositeends of' the resistance 9 and theother comprising leads 12 and 132L'connected tothe opposite ends of the resistance 9a, both shunt circuitsbeing opened and closed by any suitable automatic. device, whilecondens'els let and 1i are pret-` erably connected across the shuntcircuits to diminish sparking at the contacts of the automatlc device.The shunt circuit around resistance 9 is controlled by anfautomaticrelay i consisting of a fixed contact y15 connected to y' the lead .12and coperatlng with a movable other lead 13 and normally held inyengagement with the fixed contact by-aspring' 1T, while the shuntcircuit around resistance 9 has a corresponding'fixed lcontact 15connected to a lead 13 and cooperating with a movable armature andcontact '16a connected to the other lead 12a. The armatures arecontrolled by relay magnets 18 and 18, the magnet 1S being connected inshunt across the consumption circuit through leads 19, 20 and 21 whilethe other relay magnet 18a is also connected in shunt across the saineci rcuit by means of leads 19a, 20a and 2l, both being in series with asuitable resistance. lVheu either` relay magnet is energized `itsarmature'moves against the tension ot the restraining spring to open theshunt circuit around the corresponding regulating resistance. andthereby cuts the resistance into circuit with the field coil.

The relays controlling the two suppl \r circuits for sending currentthrough the coil (3 in opposite directionsare in turn controlled bymeans ot aV regulator' responsive 'to changes in load on thedistribution system and to the voltage`on the exciter circuit wherebythe intensity andduration of the magnetomotive force generated by thebooster is varied as the load upon the circuit and the voltage of' theexciter may determine. l

This device may assume Various forms but the preferred arrangement isthat shown in the drawingsI where the leads 19 and 19 of therelaycircuits are connected by means of' leads 31 and 31a to Vibratingcontacts and mounted on.a piyoted vibratory lever or armature 3S whichis actuated through a pin and slot connection Bt at one end, being heldin neutral position by opposing springs 35. The lever 33 is actuatedthrough the connection 34: troni oppositely disposed cores 3G and 36 ofexciter magnets or coils 3T and 3T. connected in shunt across andrcsponsive to the voltage on the exciter circuit to vibrate. the leverf-i and regulate the field 'coil o ot the exciter by short circuitingone er the other of the relays 1S and 18h. the relay 1S is drnergizcdthe spring 17 will pull the armature 1G into engagement with the fixedContact thereby short circuiting the resistance 9 and allowing` maximumcurrent to flow through the leads S. i 1.5i, 1Q and 10, the field coil(i and lead 7 in one direction. At the same time the relay 18 willremain energized and leave the resistance 9^ in circuit with the othersupply ,Cireuit. If the rela-y 1F31 is dencrgized .a reverse action willtake place. In order vthat the exciter coils 37 and 37 may control therelay magnets 1S and 1S to produce the desired effect, a floatingContact '23S mounted on varmature and contact 16 connected to the apivotcd lever 39 and connected to the lead 2l through a lead 'ii-t issituated between and operates with" the vibratory contacts 32 and 32 tocontrol thecircuits of the relays.

:its 'Fhe vibration of either contact or 32a into and out of engagementwith the floating 'contact 38 .short circuits -thejcorresponding fi'layto yproduce the effect' described.

The lever 39 is actuated bya current coniO ti'ol magnet 40 connectedthrough a variable resistance :'28 to the ends of fa shunt 29 intheconslnnption circuit-"and hence responsive to current. from thegenerator', and has its core 41 so proportioned that itfhas'a long rangei5 of movement in` responsef to com'jiaratively slight variations ofcurrent. The movement of the'core 4l is steadiedI by a dash pot 42,' and.the weight of the core is partially counter-balanced by acounterweight3 attached to the lever 39,' so that a slight increase of current aboveits normal dran-sf the core up into the coil,I and a slight decreasepermits it to sink down to tlie' position shown in the drawing. flNlrols the iosition of the floating contact 38 and alsojtliecircnitfthrough the exciter magnets 37 and 37 -byxneans of a secondary.flioating contact 44 mounted on the lever and cooperating-u'itlivieldingly supported or,

'il :30?` flexible contacts 45 a'nd 45a connected ffthrough the excitermagnet coils- 57 and 37a simi] u lead 46 lotone side of theV excitercircuit, while the secondary floating contact 44 l fis connected througha leadlT to the other '35 side of the exciter circuit. 'i vlien thecore-4l n moves downward in response to a decrease of load on thelenerator, the contacts and 45 engage and eep the circuit: through'thecoil 37 closed until the core returns to normal 40 position, while:zn-upward movement of the core diiefto increase in load keeps a. thecir cuit of the coil 37 closed until thelloaclon" the generator is againnormal. 1

ln the operation of the system her controlled by a regulator responsiveboth to load -on the. consumption circuit and toV the voltage on `theexciter circuit. When the lond on the system` is normal the currentcontrol lever 39 may bein a neutral position out of exigagementivith anyofithe contacts,

and under hese conditions the voltages in ,the two snply circuitscounteract each other and no c'nrrent flows through the field coil l5 6of the exciter. `,As 'the load `begins to decrease, the generatorattempts to psupply .less current and thecurrent control magnet 40permits the c ore 41 to sink to the posi-v The pivoted lever 39 con-zi eshown 45. the circuits through `the relay magnets are causes a currenttoflow through the exciter coil 3T and the pivoted lever 33 beglns toA-vibrate in such a manner that the field coil 6 ofithe exciter isenergized to the proper amount to cause the booster' to charge; the 7,battery at a rate lwhich maintains a constant load on the generator. Thecircuit through fthe exciter magnet 37 remainsI closed at the.

ccntactssllet' and 45 as long as the'loadfis be.

Vloiv-l normal, in spite of the fact that the crease, -the attempt v ofthe generator tog5 fnrnislr more current causes the core 41 to moreupward, bringing the contact .ll-Tl against the contact 45a, closing thecircuit throngh'tlie exciter-'coil 37a and at the same timebringing thefloating contact-:into engagement with the vibratory contact 32 to shortcircuit the relay magnet 18-andthereb y send current throughthefield'coil 6, in direction'to cause the booster to discharge thebattery into the line. As long as the load 9x5 is -abovenormal thecircuit through the exciter coil 37?re1nains'closed, and the current!through the coil, varying with the'voltage on the exciter circuit,`causes `the coil to vibrate ther'pivoted lever 33 so asf'tom'akc land.break -thecirc'uitaround the Arelay'niagnet 18 in such a manner thatthebooster is caused to discharge the battery at a a'te Whichmakes ittake its sha-re'of the loa During the time the load is changing the\I`l5 effect of the vibrations of the lever 33 .is altered by themovement of the floating contact 38', which by moving toward' thevibrating contact 32 as long as the load is in creasing lengthen-s theperiods during. which` the circuit is closed, and by moving in theopposite direct-ion as long as the load is deby the appendedv claims allchanges and -modiications Within the spirit and scope of my invention.

What I claim as new and desire to secure byLetters Patent'of the UnitedStates, is,.-

l. In a system of distribution, the combinationwith a storage batteryand a booster in series therewith connected across a circuit, of anexciter for the,VA booster, a relay"` coil for controlling the field ofthe exciter; floating contacts for short-circuiting saidfl relay coil,an exciter coil connected across the exciter circuit for moving oneof'said, contacts, means responsive to load on the system for moving theotherv of said contacts, and contacts actuated by said load responsivemeans to control the circuit through said exciter coil. y

2. In a system of distribution, thecombination Wit-lr a storage bat-teryand a booster .in series therewith connected across a main normal andthe circuit of the other coil closed when below normal.

3. In a system of distribution, the combination with. a boosterconnected to a consumption circuit, of an exciter' for t-he booster,apair of contacts for opening and closing a circuit to control the flowof current through the eld of the booster, an exciter coil in shunt tothe exciter circuit for controlling ,oneA of said contacts, a regulatingcoil in series with the consumption circuit for controlling the othercontact, and cooperating contacts in the circuit of said ex- Copiesofithispatent may be obtained for citer coil held in engagement by saidregullating coil when the load-#is abnormal.`

4.111 a system-of` distribution, the combination with a dynamo electricmachine connected to a consumption circuit, of an exciter for the fieldof said machine, supply circuits for sending current through the fieldof the exciter inA either direction, vibrat-Y ing contacts each includedin one of said supply circuits, exciter coils connected in shunt to saidexciter circuit for controlling said contacts, means coperating withsaid exciter coilsassociated with each supply Circuit 'or rende-ring thesame ei'ective, com'- prising a regulating coil in series with theconsumption circuit, and contacts controlled by said regulating coil forclosing` the circuit of one exciter coil during underloadl and of theother exciter coil during overload.

5.- In a system of distribution, the combinat-ion of a dynamo electricmachine, afield Winding therefor, an exciting circuit' for said fieldincluding a pair of vibrat-ory contacts and opposing coils for vibratingsaid contacts, a main controlmagnet responsive to the load on thesystem` for engaging with cit-her of said vibrating contacts, and asecond pair of yieldingly supported contacts also engaging With themain. control magnetl for energizlng one of said opposing coils Whilethe other is denergized. In Witness whereof, I have my hand this 12thday of December, 1907. ALLEN A. TIRRILL. lVitn-esses: .f

BENJAMIN B. HULL,

'lEELEN OR'roBD.

hereunto set k ve cents eachfl-y addressing' the Commissioner ofIotent's, ,y .Washington D. C."

